A member of a unit of the armed forces of the self-proclaimed Donetsk People's Republic, trains at a range in Donetsk, Ukraine, August 19, 2015. [Photo/Agencies]

KIEV -- Leaders of the self-proclaimed "Donetsk People's Republic" are planning to hold a referendum on seceding from Ukraine and joining Russia, the Donetsk-based Ostrov news agency reported Wednesday.

The referendum is scheduled to be held in two to four weeks after the Oct 18 local elections, said the news agency.

The ballot papers for the referendum designed in the colors of the Russian flag have already been printed, it said.

Neither the rebel leadership nor the Ukrainian authorities have commented on the report yet.

In July, leaders of pro-independence insurgents in Donetsk region said they would hold local elections on Oct 18 without Kiev's supervision as they believed that the Ukrainian government has not fulfilled its obligations under the Minsk peace agreement.

Last week, violence in eastern Ukraine has sharply escalated after several weeks of relative calmness. On Sunday night, at least 11 people, including nine civilians, were reportedly killed in Donetsk region, marking the worst casualties in the conflict since early June.

Starting in April 2014, the confrontation in eastern Ukraine has claimed the lives of more than 6,800 people and wounded almost 17,100 others, according to the latest UN estimates.